Multiple gitlab-runners

Dear All
I have one question about Multiple gitlab-runners.
I have gitlab server with 2 gitlab-runner , one runner Executor is shell and another runner Executor is docker.
both runner doesn’t have Tags (Tags : None)
how runners pickup right gitlab-ci pipeline for execute?

See this response on the forum when this question was asked before:

Thanks for your respond
i have one gitlab-ci that has 3 stage
i want stage 2 , use shell executer runner and stage 3 use docker executer runner !
how handle this senario ? could you please write sample gitlab-ci for this senario??

You cannot add tags to stages, just to specific jobs. E.g.

job1:
  stage: stage2
  tags:
    - shell

job2:
  stage: stage3
  tags:
    - docker

Many Thanks